PHP Regular Expression Exercises: Remove new lines from a string

Last update on May 31 2025 12:56:44 (UTC/GMT +8 hours)

5. Remove new lines (characters) from a string

Write a PHP script to remove new lines (characters) from a string.

Sample strings : "Twinkle, twinkle, little star,\nHow I wonder what you are.\nUp above the world so high,\nLike a diamond in the sky.";

Visual Presentation:

PHP Regular Expression Exercise: Remove new lines from a string

Sample Solution:

PHP Code:

<?php
// Original string containing multiple spaces and newlines
$str = "Twinkle, twinkle, little star,\nHow I wonder what you are.\nUp above the world so high,\nLike a diamond in the sky.";
// Using preg_replace to replace one or more consecutive spaces with a single space and removing leading/trailing spaces
echo preg_replace('/\s+/', ' ', trim($str))."\n";
?>

Output:

Twinkle, twinkle, little star, How I wonder what you are. Up
 above the world so high, Like a diamond in the sky.

Explanation:

In the exercise above,

This PHP code takes a string containing multiple spaces and newlines. It then uses a regular expression with "preg_replace()" to replace one or more consecutive spaces with a single space.

Additionally, "trim()" function is used to remove any leading or trailing spaces. Finally, it echoes the modified string.

Flowchart :

For more Practice: Solve these Related Problems:

Write a PHP script to convert all line breaks in a multiline string into a single space while preserving paragraph breaks using double newlines.
Write a PHP function to replace newlines in a string with HTML `
` tags for web display.
Write a PHP script to remove newlines only if they are followed by lowercase letters (e.g., soft-wrapped lines).
Write a PHP function that collapses all newline and tab characters in a string into a single whitespace character.

Go to:

PREV : Remove nonnumeric characters except comma and dot.
NEXT : Extract text (within parenthesis) from a string.

PHP Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.